Energy transport and entropy analysis for non-Newtonian Sutterby nanofluid flow through intersecting planes

Abstract

Designing high-performance thermal systems, such as microchannel heat sinks, biomedical devices, and polymer manufacturing equipment, require optimizing heat and fluid flow in complex geometries. By reducing irreversibility and energy dissipation in thermal systems, entropy optimization improves operational efficiency and saves energy. Owing to these facts, a mathematical model has been developed for purely radial flow of non-Newtonian nanofluid through intersecting planes subject to Jeffery-Hamel nature. The Sutterby fluid model is employed to capture the shear-thinning and shear-thickening rheology of the nanofluid, providing a realistic representation of complex transport phenomena beyond the Newtonian framework. Heat transport and entropy analysis for this model are further investigated using Buongiorno model. This is probably the first attempt to extend the classical Jeffery-Hamel problem for Sutterby model with viscous dissipation and no-slip along the channel walls. The governing momentum and energy equations, formulated via similarity transformations, are reduced to a system of nonlinear ordinary differential equations and solved numerically using Runge-Kutta Fehlberg technique with shooting method. Furthermore, a thorough entropy generation analysis is conducted to assess the irreversibility within the system due to heat transfer, fluid friction, and nanoparticle diffusion. The Bejan number is also computed to determine the dominant contributor to entropy generation. The results provide critical insights into optimizing thermal performance and minimizing energy losses in advanced thermal systems involving complex geometries and smart fluids, such as microfluidic devices, heat exchangers, and material processing systems. We have deduced from the current numerical simulations that the Reynolds number has a diametrically opposite effect on velocity for both convergent and divergent channels. For convergent channels, it is known that fluid velocity rises with greater Weissenberg number.